Davey, on Bryonia Dioica. 
101 
to me^ that if a plant of very rapid growth were subjected to 
examination without detaching the embryonic parts from the 
main stem^ the actual transition of protoplasm into cells 
might be observed. As I have not been disappointed in this 
hope, I am desirous of communicating my success to the 
Microscopical Society. 
The plant which, for various reasons, I selected for exami- 
nation is the common Bryony ; it is peculiarly well suited 
to the purpose, as it is hardy, of rapid growth, and its long, 
slender shoots are easily brought under the microscope. The 
method of examination I adopt is as follows : — a plant of 
Bryony being potted, and sufficient time having elapsed for 
recovery from the shock of removal, one of the strongest 
shoots is deprived of its leaves, &c., near the apex, until the 
soft plastic masses of embryonic parts are brought into view; 
these are washed with pure water to remove fragments, and 
placed in a compressor in water under the microscope. 
In consequence of the tapering form of the apex of the 
shoot, I have found some difficulty in compressing the soft 
parts without crushing the thicker stem l^eyond ; I have 
therefore devised a form of compressor for the purpose, which 
answers exceedingly well. It consists of a slip of glass, 
3 inches by 1, and a thinner one, 3 inches by | ; these are 
hinged together at their margins with tape and solution of 
shell-lac in naphtha ; the tape is thus fastened firmly to the 
glasses, and rendered waterproof. 
Into the acute angle formed by these glasses when opened 
a little, the prepared shoot is introduced, with plenty of water ; 
the pressure is applied by bringing down the bars of the 
stage clip upon the upper glass. In this manner I have 
easily succeeded in applying moderate pressure to the extreme 
apex, without crushing the stem through which it derives 
its nourishment. 
I will now proceed to state what I have observed, premising 
that I do not profess in this brief communication to touch 
upon all the points connected with cell- formation, nor to 
attack or defend theories, but simply to state the fact that I 
have seen the actual transition of soft plastic masses into a 
cellular condition, and to describe what appearances were 
presented during that transition. 
After the young shoot has been in the compressor for a 
short time, the semitransparent, granular mass, which is the 
most recently formed, is seen to augment gradually in bulk, 
and from being nearly colourless or of a yellowish colour, 
assumes near its centre a decided yellow-green. The edges 
of this mass, when subjected to slight pressure, are seen to 
